As a ligation device to ligate a biological tissue, for example, it has been known that a ligation device is inserted into a body cavity from a forceps port of an endoscope into a body cavity, a manipulation wire connected to a clip is pull-manipulated so as to fit the clip of which an arm part of the front end is enlarged and opened to a position of the desired biological tissue, and the arm part of the clip is closed to ligate the biological tissue (see, e.g., Patent Literatures 1 and 2).
The ligation devices for the biological tissue disclosed in Patent Literatures 1 and 2 are configured to include an introducing pipe inserted into the body cavity, the manipulation wire inserted within the introducing pipe to be freely reciprocated, and the clip connected to the manipulation wire and loaded in a front end part of the introducing pipe. The ligation devices have a structure in which the clip is detained in the body cavity in a state where the clip grips the biological tissue by pulling the manipulation wire. However, the ligation device in Patent Literature 1 forces a fitting part to be widened to be released by passage of a bulging body, but there is a concern that the deformation of the fitting part is small and the fitting is not released.
In the ligation device in Patent Literature 2, a clip constituted by a clip claw member and a pressing member is temporarily fixed to a front end of a sheath, and thus the clip claw member can be manipulated at either of an opened state and a closed state. However, since the clip is separated from the manipulation wire by fracture of a semi-circular part that connects to the clip and the manipulation wire, there is a concern that a small piece of fragment may be generated when the semi-circular part is broken. The fragment may enter into the introducing pipe of the ligation device or be detained within the body cavity. When the fragment is detained within the body cavity, there is a concern that it may cause a trouble to the manipulation of the manipulation wire that is continuously performed and sequential ligations of the biological tissues by a clip at the next step will not be performed. Therefore, it is not appropriate to a structure used for a repeating ligation device. Also, it is not preferable to detain the fragment within the body cavity inadvertently.